Certain types of machines are used in operating environments where shocks and vibrations of significant magnitude can occur frequently or continuously. Agricultural machines, forestry and mining machines and other off-highway machines such as loaders, backhoes, scrapers, track-type tractors, trucks, etc., are commonly used to travel across and interact with highly irregular substrates, and for tasks which can jar and/or vibrate the machine. Operators can be expected to work fairly long hours under such conditions, sometimes leading to premature operator fatigue and reduced operator comfort resulting from shocks and vibrations. In recent years, increased attention has been given to relatively subtle features of machine design and equipment that can help improve operator comfort and ameliorate fatigue. The layout, features and equipment at the operator station of many modern machines have seen much improvement in this regard over conventional strategies.
One area of particular interest relates to operator seating. In a wheel loader, tractor, off-highway truck and other machines, the operator typically sits in a seat within a cab where he/she has access to various machine controls. It is common for operator cabs to be mounted on resilient bumpers or the like which can dampen certain vibrations and reduce shocks between the machine body and the operator cab. Specialized seat mounting arrangements and pneumatic seat supports or “air bags” have also become common features in newer designs. There is no question that operator comfort, fatigue levels and even productivity have benefited from the adoption of improved seating technologies, however, these improvements have not come without drawbacks.
One type of seat intended to improve the foregoing concerns includes an inflatable air bag positioned between a machine seat and a machine body. An air compressor for the air bag is typically mounted either to the seat or to components of the seat assembly. An air line extends from the air compressor and connects to the air bag for supplying compressed air for inflating/pressurizing the air bag when the air compressor is activated. The air compressor housing includes an inlet and an air outlet to the air line. The air line connection to the air bag and the outlet to the air line from the air compressor housing are potential air leak paths. During operating the associated machine, the seat and air bag tend to move up and down as shocks and vibrations are experienced, potentially resulting in wear on the air line and its associated connections. Over time, leaks can develop which necessitate servicing the system or replacing components altogether. A further problem with conventional designs relates to the generally irregular shape and size of the air compressor housing, and the associated challenges to packaging the air compressor within the operator station, where space can be at a premium.